Increasingly rapid advances in laser technology along with increasingly wide scale deployment have made the deployment of laser technology to a wider variety of applications possible. The potential advantages of laser technology in terms of input to output energy efficiency coupled with engineering and economic considerations such as controllability, cost, and supplier availability has led to continuously stimulated growth in the development of numerous devices and processes to exploit the full benefits of laser technology.
Concentrated growth in the application of laser technology has been seen over the last several decades particularly in the area of optoelectronics, which, for example, makes use of semiconductor lasers for communications. However, the application of lasers beyond communications is also rapidly increasing. It is becoming increasingly common for lasers to be used as the preferred tool for numerous industrial applications such welding, soldering, marking, metal cutting, entertainment electronics, display devices, printing and the like. It is beyond dispute that laser applications, which are, by now, quite well established, have revolutionized modern day living.
However, despite the widespread use of lasers for numerous applications, as set forth above, certain areas have not seen widespread use of laser technology. For example, the potential of lasers has not been exploited in connection with domestic and commercial food preparation. In another area, food preparation technology has also taken many leaps forward. The microwave oven and various convection systems are widely available and shorten food preparation time for heating and cooking food. Yet despite advances in radiant and radio energy heating appliances, there are presently no laser-based cooking appliances available for domestic or commercial use. While conventional cooking methods including gas energy, electrical energy, and microwave irradiant energy have unique limitations, including energy cost, fire hazard, radiation hazard, which has not impeded their widespread use, heating food products using lasers has not seen any development due to various problems some of which are recognized in the art and some of which are not. Thus, while lasers are extensively used in many applications as noted above, their potential for heating food products has not been explored.
Various impediments to the development of a laser cooking appliance may include the difficulty in determining the appropriate parameters for laser cooking, the problems with the process implementation due to delicate nature of the food product materials, and the like. It may be difficult to easily initiate cooking of food products and, if cooking can be initiated, it is difficult to assure quality and uniformity of the heating or cooking process. Consequently, laser cooking of food for consumer application has not been successfully achieved.
While published research work in the area of laser cooking is quite limited and while no appliance is commercially available, the feasibility of laser cooking has improved considerably, particularly with the availability of several types of reliable laser units operating at variety of wavelengths and power levels. Despite the improved feasibility, there is still no progress in providing a laser cooking appliance.
Despite the numerous potential advantages of laser devices such as (i) the delivery of intense energy over prescribed area leading to localized heating, (ii) the uniformity, repeatability and precise control of the energy delivered, (iii) the ability to program and deliver the energy in short bursts in terms of power, pulse width, pulse repetition rate and other parameters, (iv) the lack of contact and contamination of the heated object, lasers have not been successfully used in cooking, (v) the lack of an open flame or arc, and (vi) low cost, no appliance has yet been developed.
It should be noted, particularly in connection with item (vi), that with the tremendous growth in the availability of laser devices and the implementation of mass production techniques, the cost of the laser will trend downward over time. Thus, a laser-based cooking device could be developed that would see a decreasing cost structure for its primary element. On the other hand, it is unlikely that significant cost reductions for conventional cooking appliances are possible due to the maturity of the product line. However, such advantageous conditions have not as yet been appreciated in the art by those of corresponding skill.
In addressing the lack of a laser cooking appliance, reference is made to certain problems associated with cooking of food material with a laser. Such problems are considerably more complex than may be apparent at a first glance. Extensive studies, both empirical/experimental and theoretical, are necessary in order to characterize the laser cooking parameters and determine their effects on the food product and the resulting quality of the cooked food product. Such studies and relevant data, which are of great importance for process optimization, however are not available.
As noted the use of lasers in industrial applications is known, however lasers had not been widely contemplated for food preparation and cooking due to the inherent challenges in manipulating even simple regularly structured materials such as glasses and crystalline materials. For example, in “Development of a system for laser splicing photonic crystal fiber”, Chong and Rao, Col. 11, No. 12, OPTICS EXPRESS 1365, 16 Jun. 2003, describes laser splicing by fusing materials through the application of laser energy. While some benefits were observed due, presumably, to various effects of repeated and continued application of laser energy, the specific purpose was to fuse fiber optic devices such as regularly arranged polycrystalline materials under very limited conditions.
While some attempts were made to employ lasers for cooking applications, none has resulted in a successful laser cooking appliance. For example, Japanese Patent Publication No. JP 63-003131 A2, to Terakubo Kiyoshi, published in January 1988, describes a Laser Cooking Device that completely stops the generation of poisonous gases and improves cooking efficiency. In Terakubo's device, advantages are realized by cooking food indirectly in a cooker heated by a laser. In Terakubo's device, food is not directly exposed to the laser beam.
Further, U.S. Pat. No. 5,881,634 issued to Robert K. Newton, on Mar. 16, 1999, describes a clamshell or two-sided cooking system having two platens or plates used to cook food. In Newton's system, the periphery of an upper platen is marked on a lower platen by a laser-etched wear resistant marking that withstands the scraping and scrubbing operations associated with using and cleaning the clam cooking system. The device described by Newton, does not use a laser to cook food, and provides wear resistant markings in the clamshell cooking system.
Still further, U.S. Pat. No. 5,952,027 issued to Prem S. Singh on Sep. 14, 1999 describes a using an energy source, which can be a laser, to brown an exposed surface of a pre-cooked muscle meat product. Singh's method involves only the surface of the product and requires various chemicals to assist in creating a golden brown effect on only the surface portion of the meat product.
In Japanese Patent No. JP 2002-147762 A2 published May 22, 2002, to Asano Hideki, a Food Cooking Apparatus is described that includes a microwave oven with a laser irradiation unit that irradiates a laser beam at a specific wavelength through an optical fiber onto foodstuffs in a cooking chamber. Two kinds of semiconductor lasers having different wavelengths of 0.8 μm and 1.5 μm are coupled to the respective optical fibers. The machine room is provided with a magnetron, a waveguide, and a fan to discharge heat generated. The device described in Asano has disadvantages in that it is very complex and expensive. It is not clear whether the food is cooked by microwave or laser beam. It also requires a waveform for control the cooking process.
In U.S. Patent Application Publication No. 2008/0282901, to Boris Muchnik, a method and apparatus are introduced for using a laser to cook food. A CO2 laser is directed at a beam splitter which splits the laser beam in half. Mirrors are used to focus beams to either side of the food. The CO2 laser beams are much hotter than average and as such most foods will be cooked in less than a second. Further, by cooking food at such high speeds the juices will be sealed in and the formation of trans-fats will be reduced or prevented.